Phyl& hemical Aspects带 Important for sex hormones and bile salts Excreted through bile in conjugated form as glucuronides or sulfate, but cannot be reabsorbed in this form Members of intestinal bacterial flora make glucuronidases and sulfatases that can deconjugate these compounds Physiological role not known BIOL 533 Lecture two
BIOL 533 12 Lecture Two Physical & Chemical Aspects • Important for sex hormones and bile salts – Excreted through bile in conjugated form as glucuronides or sulfate, but cannot be reabsorbed in this form – Members of intestinal bacterial flora make glucuronidases and sulfatases that can deconjugate these compounds • Physiological role not known
Phyl& hemical Aspects带 Source of carcinogens Large intestinal flora Many potential carcinogens are only active after being modified Some modifications are carried out by enzymes of intestinal bacteria; example: cyclamate converted to bladder carcinogen(cyclohexamine) by bacterial sulfatases Importance of carcinogen production not clear BIOL 533 Lecture two
BIOL 533 13 Lecture Two Physical & Chemical Aspects • Source of carcinogens – Large intestinal flora • Many potential carcinogens are only active after being modified – Some modifications are carried out by enzymes of intestinal bacteria; example: cyclamate converted to bladder carcinogen (cyclohexamine) by bacterial sulfatases • Importance of carcinogen production not clear
Ecology of Normal Flora带 Use of germ-free animals Immune systems not well developed Have to be fed vitamins BIOL 533 Lecture two
BIOL 533 14 Lecture Two Ecology of Normal Flora • Use of germ-free animals – Immune systems not well developed – Have to be fed vitamins